Front coilovers on 98 k2500 suburban

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Powderguy

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I have a daily driven 98 suburban k2500(7.4, 411's, 35's)

I ran across kits they sell for the gmt800 trucks that come with a bracket that mounts on the lower control arm and also weld on brackets for the frame for the coilover to mount. Gets rid of the torsion bars, shocks, and oe bump stop. It EVEN clears the upper control arm(although a lot of lifted guys run aftermarket ones). Is this something that's been done on our trucks before? Keep in mind I'm talking k2500 not k1500.

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This is the kit on a 1500 gmt800 stock height truck

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Same kit except longer coilovers and aftermarket UCA and longer spindles. THIS IS ALMOST IDENTICAL TO WHAT I WANT TO DO.

Right now I'm running a 3" body lift and torsion crank to clear 35's...

I've got a donor truck to pull the frame from so I can hack and weld on it at my leisure while I box it in and powder coat it, this way I can experiment without worry of making irepairable damage to my existing frame.


Plan was to get a 6" suspension lift and install on new frame before body swap, BUT Coilovers sound so much nicer from what people are saying with those kits....

WHY DO I WANT COILOVERS?

1. Ride quality
2. Cool factor

I only do occasional off-roading and need the truck to tow at a moments notice with my job. My last suburban had a 6" lift that was doable but I personally think the kits they make for these trucks that drop the upper control arm aren't as good as a knuckle drop kit that puts more distance between the LCA and UCA. I want better ride quality and adjustability.

HERES MY PLAN:

1. Either buy or fab the bracketry to drop the LCA and diff 6". I already called tuff country and superlift and I can buy parts of kits through suppliers. Or maybe someone on here has a lift they would let go for a reasonable price?

2. Buy 6" lift spindles for a gmt800 2500(fabtech sells for like ~$500). UCA would remain in stock location like many aftermarket kits for nbs trucks. The reason for a NBS spindle is because the stock gmt800 spindles work on these trucks with very minor modifations and have much better brake options. AND the way I look at it is if there winds up being a clearance issue with the UCA I can buy an aftermarket one for a gmt800 that bolts right to the spindle and modify the frame mounts if necessary.


My truck has the forged lower control arms(not stamped) I feel like it could handle bearing the weight just fine if the mount was designed right. Upper mounts would be a simple weld on tabs deal and possibly a hoop(oe shock mount and bump stop would have to be removed)

Clearance with the stock upper control arm is my biggest concern but I really think it could be sorted out. I do powder coating for a living and have a hydraulic pipe bender, plasma, welder, etc, of my own. If I get stumped, I know every welder, machinist, and 4x4 shop around here so they can make things easier if something had to be made..say.. a 1 piece machined lower mount for the coilover?

I have time, resources, and plenty of barter leverage with all the metal workers I coat for too.

What are everyone's thoughts before I start buying parts? Any suggestions? I want a GOOD ride, the stock ifs is plenty strong enough for my uses so please don't say just do sas swap man..
 

Smith

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I wouldn't trust the upper shock mount nor the control arms to bear the weight of the truck with it all centralized on one spot of a coilover. With a coilover you also have to keep in mind you are now placing the entire weight of the truck on that coilover and its mounts. With this you are creating a leverage point on the frame. I would want to make a crossmember that ties both sides of the frame together to keep it from wanting to roll inwards towards the engine. This may work without the crossmember on a newer truck frame but these newer frames are much stronger and are designed better than the frames on our trucks
 

Powderguy

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I wouldn't trust the upper shock mount nor the control arms to bear the weight of the truck with it all centralized on one spot of a coilover. With a coilover you also have to keep in mind you are now placing the entire weight of the truck on that coilover and its mounts. With this you are creating a leverage point on the frame. I would want to make a crossmember that ties both sides of the frame together to keep it from wanting to roll inwards towards the engine. This may work without the crossmember on a newer truck frame but these newer frames are much stronger and are designed better than the frames on our trucks

Very true. Other companies like BDS include a similar brace in their coilover conversion kits for newer trucks. The guy that makes these kits specifically says beef up the frame in that area too.

As far as centralizing the weight on the control arm there are many people running his setup on lifted 1500 trucks(38"+ tires) with a less meaty LCA than what's on my truck with no problems...I would have to come up with a bracket that distributes the weight similar to his and I think problem solved. Assuming our cast lowers are just as strong as newer 1500s lowers.
 

michael hurd

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I have a daily driven 98 suburban k2500(7.4, 411's, 35's)

I ran across kits they sell for the gmt800 trucks that come with a bracket that mounts on the lower control arm and also weld on brackets for the frame for the coilover to mount. Gets rid of the torsion bars, shocks, and oe bump stop. It EVEN clears the upper control arm(although a lot of lifted guys run aftermarket ones). Is this something that's been done on our trucks before? Keep in mind I'm talking k2500 not k1500.

You must be registered for see images attach

This is the kit on a 1500 gmt800 stock height truck

You must be registered for see images attach

Same kit except longer coilovers and aftermarket UCA and longer spindles. THIS IS ALMOST IDENTICAL TO WHAT I WANT TO DO.

Right now I'm running a 3" body lift and torsion crank to clear 35's...

I've got a donor truck to pull the frame from so I can hack and weld on it at my leisure while I box it in and powder coat it, this way I can experiment without worry of making irepairable damage to my existing frame.


Plan was to get a 6" suspension lift and install on new frame before body swap, BUT Coilovers sound so much nicer from what people are saying with those kits....

WHY DO I WANT COILOVERS?

1. Ride quality
2. Cool factor

I only do occasional off-roading and need the truck to tow at a moments notice with my job. My last suburban had a 6" lift that was doable but I personally think the kits they make for these trucks that drop the upper control arm aren't as good as a knuckle drop kit that puts more distance between the LCA and UCA. I want better ride quality and adjustability.

HERES MY PLAN:

1. Either buy or fab the bracketry to drop the LCA and diff 6". I already called tuff country and superlift and I can buy parts of kits through suppliers. Or maybe someone on here has a lift they would let go for a reasonable price?

2. Buy 6" lift spindles for a gmt800 2500(fabtech sells for like ~$500). UCA would remain in stock location like many aftermarket kits for nbs trucks. The reason for a NBS spindle is because the stock gmt800 spindles work on these trucks with very minor modifations and have much better brake options. AND the way I look at it is if there winds up being a clearance issue with the UCA I can buy an aftermarket one for a gmt800 that bolts right to the spindle and modify the frame mounts if necessary.


My truck has the forged lower control arms(not stamped) I feel like it could handle bearing the weight just fine if the mount was designed right. Upper mounts would be a simple weld on tabs deal and possibly a hoop(oe shock mount and bump stop would have to be removed)

Clearance with the stock upper control arm is my biggest concern but I really think it could be sorted out. I do powder coating for a living and have a hydraulic pipe bender, plasma, welder, etc, of my own. If I get stumped, I know every welder, machinist, and 4x4 shop around here so they can make things easier if something had to be made..say.. a 1 piece machined lower mount for the coilover?

I have time, resources, and plenty of barter leverage with all the metal workers I coat for too.

What are everyone's thoughts before I start buying parts? Any suggestions? I want a GOOD ride, the stock ifs is plenty strong enough for my uses so please don't say just do sas swap man..


How long do you figure those rod ends on the QA1's will last even on a weekend warrior, let alone a daily driver?

There is a reason the factory and others use a rubber or urethane compliance bushing, it will outlast that rod end many, many times.

Having a 'good' ride is subjective. One person's good is terrible to another. Replacing degraded control arm bushings, sway bar bushings and end links will do wonders for your ride quality.

Heavy wheels and tires need more damping, however many owners use wheels that offset the wheel in excess proportion towards the outside of the body. This has a net effect of lowering the ride rate of the spring. [ moving the weight farther out increases leverage over the torsion bar or other spring ]
 

BerHntr

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^^^ my ride improved considerably after I took the 2" wheel spacers of mine the other day.
 

RussKincaid

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I have a 95 k2500 and have had similar thoughts. Weld on a sturdy shock hoop for your upper mount and build a bolt on cross brace across the top of the motor like the ricers do. that should keep the frame sturdy enough on top. the bottom I haven't quite figured out but if the baja guys are running coil overs, you know there's something out there stout enough for us.
 

SubWarrior

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I'm really stoked to see where you are going to go with this. I've been wanting to do the same thing on my truck but I know very little about suspension. I would imagine the forged LCA has the strength, but the top shock mount needs to go and the frame needs some more support.

Have you considered using some parts from the gmt900 series trucks? They run a McPherson strut design up front which I think would be a better foundation for a coil over conversion.
 

Project400

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I'm considering this too.
I have no need for a SAS. I want the ride quality of the ifs.

Improved wheel travel and more compliance off road would be nice and the only reason I'm even considering it.

The added wheel travel makes CV angles more important. You will want them much closer to parallel to the road (middle of travel)
 
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